block featured image

Hello, sorry for the English. In WordPress is the ability to add featured image (preview image) to the post using the right panel I would like this option but needed something to block, go ahead and delete but that was not there to see that possibility. Only that he put a picture up in the article is there any possibility? in codes I could find. If you do not understand that Google Translate English, and I apologize if I write it briefly and succinctly.